Vacuum-feed carbureter.



T. W. BURH.

VACUUM FEED CARBURETER.

APPUCATIOH "LED JUNE 30.1916. 1 ,271,848. Patented July 9, 1918.

W'Zneas, Jr: 0871302,

THOMAS WILLIAM BURR, OF STONEFIAM, MASSACHUSETTS.

VACUUM-FEED CABBURETER.

Specification of Letters Patent.

Patented July 9, 1918.

Application filed June 80, 1918. Serial No. 106,985.

reters employing a 'vacuum feed, as dieting? guished from a gravity feed. s Prior to my invention, varlous forms of vacuum feed devices have-been produced which are designed to give a constant f to the carbureter, irrespective of the hei ht of the liquid in the main supply tank, ut these devices have generally been of ex 11- sive construction or unsatisfactory in t eir operation in certain particulars. 5

The object of my invention is 'so" to improve existing devices, of the general character above referred to, that the feed of the liquid to be carbureted will be as nearly uniform as ossible, under all conditions, and, also, to simplify devices of the general character above referred to, so that the feed will be as nearly uniform as possible under all conditions, and also, to simplify devices of this character so that the cost of manufacture may be substantially reduced.

In the accompanying drawings, in which an embodiment of my invention is shown, Figure 1 is a central vertical sectional view of a carbureting apparatus, embodying my invention. Fig. 2 is a sectional view on the line 2-2 of Fig. 1.

Fig. 3 is a sectional view on the line 3-3 of Fig. 1.

In the drawireig, a main casln a of tubular form is provid having an all intake assage 6 leading thereto at one side and a jacent its lower end, and an outlet passa e c which is connected to the intake mani old of the engine, said air intake passage having the usual spring-pressed check valve d,

and being connected to a pipe 6, which preferably leads from about the exhaust manifold, so that the air is heated as it is drawn in. The outlet passe. isprovided with a throttle f of common orm.

According to my invention, I provide an air-tight, or a closed receptacle 9 in the easing a, which is prefers mounted on a base g, threaded mto the ower end 'of said needle va casing, said receptacle being of tubular form and of substantially less diameter, externally, than the internal diameter of the easing, so that an annular space is provided therebetween, into the lower end of which said air inlet-passage leads. A conically shaped nozzle h is threaded into-the upper end of said receptacle g, said nozzle having a tubular portion h adapted to depend in said recelptaclc for a short distance. A

vs 1 is threaded into the bottom of the receptacle g, and is arranged in alinement with the passage through the tube h, and in position to seat in the end of said tube, to vary the size of the passageway therethrough. A suitably vented supply tank 7' for the liquid fuel, or gasolene is arranged below the level of the upper end of the receptacle g, and is connected thereto by a supply pipe is, which depends therein to a point adjacent its bottom and extends u wardly throu h the casing 11 and into t e receptacle 9 c osely adjacent its up er end, and at a point above the level of t e lower end of the dependin tube h, so that, when the rece tacle g is filed to the level of the point 0 entrance of the pipe k'therein, the

"rectly to an engine cylinder, so that when the engine is turned over by hand, or by a self-starting device, a partial vacuum will immediately be formed within said casing, and, as the rece tacle g is in open communication therewitli through thenozzle h, the

'air pressure will also immediately be reduced in said receptacle to such an extent that the atmospheric pressure on the surface of the liquld in the main su ply tank 7' will force the liquid therein up t rough the pipe in into receptacle g, whp? 'wjll soon become filled to the love at, lower end of the pipe b, so that the liquid will be fdroed up said pipe h, and discharged through the nozzle it into the casing-fa, this action continuingso long as a vacuum is maintained in the casing b the engine.

As the jet-of liqui whichwill be discharged from the nozzle h is directed vertically upward, it will fall in a spray at all sides of the receptacle, the upper end of the casing acting as a deflector to break up the drops of liquid. To cause the liquid fa ling on the top of the receptacle 9 to be readily discharged into the space about it, its top is made in conical form as shown.

The suction action of the engine operates to lift the check valve d and draw air into and through the casing in the usual manner, so that, as the air passes up through the easing it meets the falling spray of liquid from the nozzle, and becomes thoroughly mixed therewith, and the carbureting operation is effectively performed. The tension of the spring n which holds the check valve d against its seat is so adjusted by the screw 0 that the air pressure necessary to lift it from its seat is greater than that necessary to force the liquid from the main tank into the receptacle 9, and into the casing a, so that the vacuum which is formed in the easing a will always be sufficient to cause the discharge of the liquid from the nozzle h.

In practice, the partial vacuum created in the receptacle 9 will be sufficient to cause enough additional liquid to flow from the tank 9' to fill said receptacle to a level at which the lower endof the pipe It will be con stantly sealed to the depth of about oneeighth of an inch. As the engine continues to operate, the conditions thus established will be constantly maintained, the liquid bein discharged constantl through the nozz e h with sufficient rapidity to meet the requirements of the engine and the rapidity of the discharge varying according to the speed of the engine, increased speed of the engine increasing the extent of the vacuum, and thus increasing the rapidity of discharge through nozzle it.

As previously stated, the air which is drawn in through the pipe e is preferably heated from the exhaust, and the air inlet port is so arranged that the heated air is caused to pass into the lower portion of the annular space about the receptacle 9, so that it will have a tendency to heat the liquid therein, as it passes upward in the casing. As a result, after the engine has been operating for a short time, the liquid will be heated to a substantial extent before it is mixed with the air, so that the carbureter will be more effective and eflicient, it being a known fact that if the temperature of gasolene is raised to a substantial extent above ordinary temperatures before it is vaporized, the vaporization will be much more nearly perfect than it would be at the lower temperature.

After the needle valve 71 has been properly adjusted for a normal speed of engine, further adjustment thereof will, ordinarily, be unnecessary and the operation will be entirely automatic, and dependent on the speed of the engine.

As a constant balance is maintained, while the engine is running, between the air pressure within the casing a, and the atmospheric ressure 'within the tank j, a constant flow of iquid from the tank j into the receptacle g will be caused, said flow being practically the same in amount as the amount discharged from the nozzle, and this amount will not be substantially affected by variations in the level of the liquid in the tank j, as the air pressure in the top of the receptacle will be automatically decreased as the liquid level in the tank is reduced, although this ressure will be maintained, when the engine is operating, at some point which is 1055 than atmospheric pressure, but greater than that in the casing. It is, therefore, possible to locate the main reservoir at a considerable distance below the level of the carburetor, provided the spring tension on the air check valve d is properly adjusted.

By having the inlet pipe enter the receptacle above the level to which the latter may be filled, all possibility that the pipe is may act as a siphon, when the engine is at rest, so as to withdraw the liquid from the receptacle, is avoided, so that after the receptacle has been once filled sufliciently to seal the end portion of the tube 10 liquid will be drawn from the receptacle as soon as the engine is turned over. The receptacle thus acts as a supplemental liquid fuel reservoir, for two purposes, viz, to provide an immediate supply of liquid, when the engine is turned over, and to provide a means whereby the liquid may be heated b the air to be carbureted, so that more e cient carburation andincreased freedom of discharge may be secured, these purposes being, in a sense, incidental to the more important feature of the provision of efiicient and effective means for causing the en 'ne, by its suction action, to draw the fuel om a tank located at a lower level than the carburetor, and for avoiding the necessity of employing a float operated valve to control the feed of the liquid fuel to the carburetor.

I claim 1. In combination with a carbureter havmg a low-pressure chamber, a low-level,

main, liquid-fuel reservoir, a closed aux- Y iliary reservoir, adapted to permit a partial vacuum to be maintained therein, a liquid supply pipeleading from a low level 1n said main reservoir and opening into said auxiliary reservoir at a hi her level than thereto and having its outlet 2. In combination with a carbureter having a low ressure chamber, a low-level, main, liquiri fuel reservoir, a closed auxiliary reservoir, a liquid supply pipe leading from a low level in said main reservoir and opening into said auxiliary reservoir adjacent its top, and a fuel discharge pipe providing the sole means of communication between said auxiliary reservoir and said chamber, and having its inlet opening to said auxiliary reservoir at a lower level than at which said supply pipe opens o ening into said chamber at a higher level than that of its inlet.

3. A carbureter comprising a casing having a hot-air inlet-port at its lower end and a suction art at its upper end, an airtight receptac e disposed within said casing to provide a surrounding chamber between the exterior of the receptacle and the interior of the casing and to the lower and upper ends of which said inlet and dis- 0 arge ports respectively lead, a liquid-fuelreservolr having a su ply pipe leading therefrom at a point be ow the liquid level therein and opening into said receptacle at a point above said liquid level and adjacent the upper end of said receptacle, and a discharge tube leading from said receptacle at a point below the discharge end of said supply pipe and opening into said casing above the top of said receptacle.

4. A carbureter comprising an upright tubular casing having an air-inlet port and a suction port in its side walls adjacent its lower and upper ends respectively, a tubular-air-tight receptacle disposed within said casing and having its bottom closing the lower end of said casing and providing an annular space between its walls and the walls of the casing, a discharge tube extending through the top of said receptacle and depending therein, a reservoir having a supply pipe connected thereto adjacent its bottom and connected to said receptacle above the lower end of said tube, and a needle valve extending through the bottom of said receptacle and arranged in operative relation to the lower end of said tube, to vary the liquid flowtherethrough.

5. A carbureter comprising an upright tubular casing having an air-inlet port at its lower end and a suction port at its upper end, a similarly-shaped, air-tight receptacle disposed within said casing and providing an annular space between its walls and the walls of said casing, a dis charge nozzle extending vertically from the middle of the top of said receptacle and having a tube connected thereto and deending into said receptacle, and a liquid- ?uel-reservoir having a supply pipe connectedthereto at a point below the liquid level therein and extending upwardly and connected to said receptacle above said liquid level and above the lower end of said depending tube.

In testimony whereof I have signed my name to this specification.

THOMAS'WILLIAM BURR.

Witness:

L. H. HARRIMAN.

Copies of thin patent may be obtllned for five cent: each, by addressing the "commissioner of Patents, Washington, D. 0. 

